New results on disturbance rejection for energy-shaping controlled port-Hamiltonian systems
For control engineers working with port-Hamiltonian systems, this provides a more general robustification technique for disturbance rejection, though it is an incremental extension of prior work.
This paper presents a method to robustify energy-shaping controllers for port-Hamiltonian systems by adding integral action to reject unknown additive disturbances, extending previous work to systems with non-strictly convex Hamiltonians and underactuated mechanical systems. The method preserves the pH structure and avoids unnatural coordinate transformations.
In this paper we present a method to robustify energy-shaping controllers for port-Hamiltonian (pH) systems by adding an integral action that rejects unknown additive disturbances. The proposed controller preserves the pH structure and, by adding to the new energy function a suitable cross term between the plant and the controller coordinates, it avoids the unnatural coordinate transformation used in the past. This paper extends our previous work by relaxing the requirement that the systems Hamiltonian is strictly convex and separable, which allows the controller to be applied to a large class of mechanical systems, including underactuated systems with non-constant mass matrix. Furthermore, it is shown that the proposed integral action control is robust against unknown damping in the case of fully-actuated systems.